This invention relates to a supporting device for detachably supporting the core of a rolled label strip on a label printing and applying machine.
A widely used supporting device for a rolled label strip is comprised of a pair of flexible supporting plates that are arranged to define a U-shape as viewed from above the machine. Each plate is provided with a round projection on the inside facing walls of the U. To attach a rolled label strip to this labeling machine, the inner bore of the core of a rolled label strip is fitted to the projections on the walls. In this supporting device, the supporting plates are bent open in every attaching and detaching of the core. As a result, the supporting plates are liable to be deformed or damaged after repeated uses, and the rolled label strips will thereafter not be supported firmly.
Known label strip supports are described in "Core Supporting Device for Label Strip in Label Printing and Applying Machine," Japanese Patent Application No. 10960 of 1975 and "Supporting Device for Label Strip," Japanese Utility Model Application No. 48862 of 1975 both of which applications were filed by the assignees hereof.
In the supporting device disclosed in the above applications, the inner bore of the label strip is detachably supported by flexible supporting pieces projecting from the labeling machine. The supporting pieces have tabs on them. There are core supporting rotary members on the flexible supporting pieces and these pieces are pivoted to the side arm plates formed above the label printing and applying machine. When the label strip rolled on the core is pulled out, proper tension is always imparted to the core to inhibit its rotation.
However, in use, it has been found that a supporting device provided with the flexible supporting pieces having tabs have a number of disadvantages:
(1) The supporting pieces having tabs must be of short length due to their structures. Thus, they can have only slight flexibility, and the core must be fitted on them with strong pressure.
(2) When the core is disengaged from the supporting pieces after the label strip has been used up, the core must be forcibly disengaged by twisting it. It is difficult for the operator to know precisely how much force to apply. In addition, the supporting pieces are often damaged.
(3) After many cores have been used, the supporting pieces lose their flexibility and the supporting force becomes weak. This may result in undesired disengagement of the core during use of the labeling machine.